OP04.05: Prediction of the risk of intrapartum fetal distress using maternal hemodynamics

Abstract

The aim was to investigate the predictive accuracy of maternal cardiovascular variables for predicting operative delivery due to presumed fetal compromise in women undergoing induction of labour (IOL). This was a prospective cohort study conducted at St. George's University Hospital in London. Women undergoing IOL were invited to participate in the study. A USCOM-1A monitor was used for the cardiovascular evaluation of eligible women. Cardiac output (CO), cardiac index (CI), stroke volume (SV), stroke volume index (SVI), systemic vascular resistance (SVR) were assessed. Women who delivered via either caesarean or instrumental delivery with an abnormal cardiotocography tracing were evaluated in the operative delivery due to presumed fetal compromise group. A total of 99 women were recruited and four women were later excluded due to elective Caesarean (n=2) and failed IOL (n=2). In the univariate analysis, a CI < 2.9 L/minute (p = 0.043), SV < 65 mL (p = .027), stroke volume index (SVI) < 36 ml/m2 (p = 0.014), SVR > 7.2 logs (p = .020) and SVRI > 7.7 logs (p = 0.023) were significantly associated with the risk of operative delivery. Multiparity was the only maternal risk factor that showed a significant association with the risk of operative delivery in univariate regression model. The baseline model (parity) showed poor predictive accuracy with an area under the curve (AUC) value of 0.67 (95% CI: 0.58-0.77). The addition of SVI < 36 ml/m2, SVR>7.2 logs and SVRI>7.7 logs significantly improved the baseline model (p = 0.012, p = 0.026 and p = 0.012, respectively). The predictive accuracy of models had AUC values of 0.73 (95% CI: 0.64-0.82), 0.73 (95% CI: 0.63-0.84), 0.73 (95% CI: 0.64-0.82) for the combined models with SV, SVR and SVRI respectively. We demonstrated that maternal cardiovascular assessment could be useful for assessing the risk of intrapartum fetal compromise necessitating operative delivery. The addition of SV, SVR and SVRI significantly improved the predictive accuracy of the baseline antenatal model in women undergoing IOL. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.